Train dispatching system for railroads



R. PLANK 2,085,039

TRAIN DISPATCHING SYSTEM FOR RAILROADS Filed Nov. 25, v 1929 2Sheets-Sheet l iNvENTRZ I WMWw, 4454/ ATTORNEY June 29, 1937.

June 29, 1937. R. PLANK TRAIN DISPATCHING SYSTEM FOR RAILROADS FiledNov. 25, 1929 2 Sheets-Sheet 2 ENTOR BY @ATTORNEY NMH OmA A Q Q3 Q3 mQKmW TE U. v n M 3: n3 um m T vsfl N2 3: ms

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Patented June 29, 1937 @NETEQ STATES PATENT @FFEQE TRAIN DISPATCHINGSYSTElvI FOR RAILROADS Application November 25, 1929, Serial No. 409,606

27 Claims.

This invention relates to a train dispatching system of the waysidesignal directing type, and more particularly to a synchronous selectorsystem, in which synchronous apparatus is controlled and in whichindications are transmitted over the same line circuit.

In my prior patent, Patent No. 1,852,367, dated April 5, 1932, I havedisclosed a, synchronous selector type train dispatching system, whichrequires three line wires, and if desired an additional checking wire,and the present invention has the advantage of requiring only two linewires, that is one line circuit.

There are many other advantageous features 15 in the dispatching systemof the present invention, which will in part appear from theaccompanying drawings and will in part be pointed out in the detaileddescription hereinafter.

In describing the invention in detail, reference will be made to theaccompanying drawings, in which:

Fig. 1A illustrates the apparatus in the dispatchers ofiice; and

Fig. 13 illustrates the apparatus located at one of a large number ofway stations. Figs. 1A and 13 if laid end to end illustrate a completeworking portion of the entire system.

Considering the present invention generally, the line circuit isallotted alternately for the pur- 30 pose of functioning as a steppingcircuit and as a message circuit. Although this allotment of the linecircuit may be accomplished in many Ways, in the particular embodimentof the invention shown, it is accomplished by having two line relays ateach way station, one of which responds a only to direct current of onepolarity, while the other responds only to direct current of the otherpolarity, and the dispatchers office apparatus includes a pendulumtiming device PTD 40 which alternately connects the stepping mechanismand the message mechanism of the dispatchers oiilce to this linecircuit. It is believed expedient to first consider the structuralfeatures of the system and then take up the operation of 5 the system.

Structure.ln accordance with the present invention, each diverging pointof a railway system, such as a spur track, or the end of a passingsiding, has associated therewith suitable syn- 50 chronous apparatus,and this location together with its apparatus will hereinafter be termeda way station. Although, in practice, there will be many such waystations in each system, for convenience only one such way station hasbeen 55 illustrated in detail, namely, the station at the west end ofthe passing siding PS, the way station at the east end of the passingsiding PS having been illustrated conventionally by the square Waystation 2.

The passing siding PS has its track rails divided by insulating joints26 in the usual way, to provide the usual detector track circuit, ofwhich the detector track circuit at the west end of the passing sidingPS includes a track relay T and battery 21, whereas the detector trackcircuit at the east end of the passing siding is provided with adetector track relay T and a track battery 28. The passing siding PS isprovided with the usual switch machines for controlling the trackswitches at the ends of the passing siding, of which the switch machineSM only has been shown, and is provided with the usual way side signalsfor directing train movements into and out of such passing sidings, ofwhich signals the signal S only has been illustrated for conven- 1ence.

In accordance with the present invention, the entire railway system ispreferably duplicated in miniature in the dispatchers office, so thatthe levers, as well as suitable indicators may be located with respectto such miniature track layout, and the correlation of these levers andinclicators with the miniature track layout will readily inform thedispatcher the purpose of each lever and indicator, without makingreference to some other designation. For convenience, only the miniaturepassing siding ps of this miniature track layout has been illustrated.

Associated with the west end of this miniature passing siding ps is anindicating lamp I, which is controlled by the indication relay IE andwith the same end of this miniature passing siding gas is associated alever L for controlling suitable traffic controlling apparatus, such asswitch machines, d-erails or signals, and in accordance with the presentinvention this lever L is only used for controlling the signal S locatedat the west end of the passing siding PS (see Fig. 1B).

In the dispatchers office is also located a 1'0- tary synchronousselector RS which includes a shaft 38 having 3 rotatable arms A A and Aassociated therewith, which arms synchronously rotate over suitablecontacts all in a manner more clearly described hereinafter. The shaft30 may be driven by suitable step by step mechanism, such for instanceas shown in my prior patent to which reference has been made, or may beof the type conventionally illustrated, in which the shaft 30 is rotatedby suitable electromagnetically operated ratchet mechanism. In thearrangement shown, the ratchet wheel 33 is prevented from rotatingbackwards by a pawl 34, and may be ratcheted in a clock-wise direction,as indicated by the arrow, through the medium of the spring 35 and thepawl 36 one step for each attraction and release of the armature 37 bythe electro-magnet 38.

The dispatchers ofiice equipment includes a line relay LR, whichresponds to current of negative polarity, and also includes relays 80,ill, SAR, SCR, SR SR SR IE IE9, FSR and FSR Referring now to thesynchronous control apparatus located at the west end of the passingsiding PS (see Fig. 1B) there is provided a similar rotary synchronousselector RS This rotary selector BS is provided with contact arms A andA the shaft 36 is operated by suitable ratchet mechanism, which isidentical to that shown in Fig. 1A except that the armature 31 carries amovable contact 39 insulated therefrom.

The way station apparatus also includes a line relay LR a signal controlrelay KR a repeater control relay KH a signal cancelling relay CR, and aslow acting relay SLR. The way station apparatus also includes aninterrupter ITR for the purpose of generating an alternating current,when required, by energy derived from a local battery 40.

Operation.-Let us assume that the dispatcher located in the dispatchersofiice, shown in Fig. 1A, wishes to clear the signal S at the west endof passing siding PS in Fig. 13, this on the assumption that traflicconditions in advance of the signal S are favorable and the home relay Hgoverned in accordance with such traffic conditionsis energized. Undernormal at rest conditions of the apparatus there are no impulsestransmitted to the way station apparatus over the transmission line,comprising the line wire 45 and the common return wire 46. This isbecause'no stepping current can flow with the stepping control relay SCRdeenergized, as the front contact 41 of this relay SCR is included inthe stepping circuit. In this connection, attention is directed to thefact that even though the synchronous selector system is at rest, so tospeak, the pendulum timing device PTD is continuously operated. Thispendulum device PTD is kept in motion by the electro-magnet 48attracting the pendulum armature 49 intermittently, this by reason ofintermittent closure of the following circuit:-beginning at the battery50, contacts 5| biased against a stop 52, electro-magnet 48 back tobattery 50. It is thus seen that with the pendulum 49 once in motion itwill remain in motion by the electric energy intermittently flowing inthis circuit.

Let us assume that in order to clear the signal S, the dispatcher moveshis lever L to the dotted position, thereby causing momentary closure ofthe following circuit:-beginning at the terminal B, contacts 55, 56 and51 (these contacts only closing the circuit momentarily this by reasonof the provision of the stop 58), wires 59, 60 and fil winding of therelay SR wire 62, upper winding of the relay SR to the common returnwire C.

The closure of this circuit causes the relays SR and SR to be operatedto their attracted positions, thereby closing the following two stickcircuits:-(1) beginning at the terminal B, contacts 63 and 64, wire 65,stick contact 65, wire 6|,

winding of the relay SR wire 62, upper winding of the relay SE to theother terminal C of the battery containing terminal B; and (2) beginningat the terminal B of said battery, contacts 63 and 61, wire 68, stickcontact $9, wire ll, lower winding of the relay SR to the terminal C ofsaid battery.

With the relay SR, energized the following circuit for energizing therelay 1!! is closed the next time the pendulum 49 swings to theright:-be ginning at the terminal B, wire 54, pendulum contact 83, wire14-, back contact of the relay Hi (this contact 75 being amake-before-break contact in that its front and back contact connectionsare made in over-lapped relation), wire l6, Winding of the relay '10,wire "H, front contact 78 of the relay SR wire l9, zero contact 0-,contact arm A to the other terminal C of said battery. The flow ofcurrent in this circuit causes the relay ill to pick up and stick upthrough the following stick circuit:beginning at the terminal B of saidbattery, wire 12, stick contact 15 of the relay ll], wire 76, winding ofthis relay l4, wire ll, front contact 18 of the relay SR wire 79,contacts 0 and A back to the terminal C.

Picking up of the relay is opens the normal energizing circuit for therelay 8!], which may be traced as fo1lows:beginning at the terminal B ofa suitable battery, wire 86, back contact 82 of the relay l0, wires 83and 84, winding of the relay 88 to the other terminal C of said battery.These successive actions of the relays SR SR and relay lfi take placeduring the time the pendulum 49 swings toward the left, and. as thependulum 49 again swings to the right, and so long as it remains there,the relay 8!] is maintained energized through the followingcircuit:--beginm'ng at the terminal B of a suitable battery, flexiblewire 54, contact 73 of the pendulum timing device PTD, wire 14, frontcontact 85 of the relay 10, wire 86, front stick contact 81 of the relay88, wire 84, winding of the relay to the other terminal C of saidbattery. This circuit will of course only remain closed while thependulum 49 is to the right of its pendent position, and assures thatthe relay 86 maintains its contact 8? closed during this period of theoperation of the pendulum.-

The relay in is, of course, now stuck upthrough the medium of its frontcontact 15. Through the medium of its front contact 9i it maintains theslow acting relay SAR energized through a circuit readily traced in thedrawings. As the pendulum 49 swings to the left. it drops the relay 80and upon its next swing toward the right, it closes the followingcircuit for energizing the stepping control relay SCR:-beginning at theterminal B of a suitable battery, wire 54, contact 13 connected to, butinsulated from the pendulum 4%, wire l4, front contact of the relay Ill,wire 86, back contact Bl of the relay 8t, wire 93, back contact 94 ofthe relay SCR (this contact 94 being a make-before-break contact, inthat it makes its front and its back contacts in over-lapped relation),wire 95, lower winding of the relay SCR to terminal C.

This relay SCR will of course pick up, and with the relay SAR energized,the following stick circuit for the relay SCR is closed: beginning atthe terminal B of suitable battery, front contact 955 of the relay SAR,wire 97, front contact $4 of the relay SCR, wire 95, lower winding ofthe relay SCR to the other terminal C of said battery.

With the relay SCR now energized and the pendulum 49 to the left, thefollowing circuit for energizing all of the various line relays, one ateach way station of which the line relays LR, and LR only have beenshown, is closed:-beginning at the positive terminal of the batterylllil, wires it! and H02, contact :03 connected to, but insulated' fromthe pendulum 49, line wire 5, through each of the various line relaysLR, LR etc., wire 46, contact 14, connected to, but insulated from thependulum 49, wire W5, front contact 41 of the relay SCR, wires Hi8, Hilland E68, to the negative terminal of the battery I613.

The closure of this circuit causes the line relay LR to be operated.towards the left, thereby causing the electromagnet 38 of the ratchetdevice to be energized through a circuit readily traced in the drawingsand including the biased contact Hi9 of the line relay LR. This linerelay LR will of course only operate to its left hand dotted position inthe eventthat it is energized by current of the negative polarity, as istrue of the circuit just traced through the line relay LR. This circuitwill of course be maintained closed only for a short time, in that itwill be interrupted when the pendulum 49 swings toward the right of thependent position. After this of course, the spring 35 operates theratchet wheel 33 toward the right one step through the medium of the dog36, so that the contact arm-s A A and A will all be moved from the zerocontact to the number I contact.

Movement of the contact arm A from the zero contact to the contact Icauses the stick circuit for the relay 1D to be broken, which will ofcourse effect deenergization of the relay l0 and in turn effectdeenergization of the slow acting relay SAR. The relay SCR will however,not assume its deenergized position even though its lower winding wasenergized through front contact 96 of the relay SAR, because its upperwinding is now energized through the following circuit: beginning at theterminal B of a suitable battery, upper winding of the relay SCR, wireHE stationary contact 1, rotary arm A to the other terminal C of saidbattery. Since all of the stationary contacts I to 24, inclusive,associated with the arm A are connected together and to the upperwinding of the relay SCR, this relay SCR will remain energized duringrotation of the shaft 36 until the arm A again reaches the zero contact0. The line relay LR will of course, be intermittently operated towardthe left each time that the pendulum 49 swings to the left and closesthe circuit of the various line relays. From this it will appear thatthe synchronous selector HS in the dispatchers office will be operatedstep by step, one step for each swing of the pendulum 49 toward theleft.

For reasons which will be more clearly pointed out hereinafter a messagecircuit may be completed during each swing of the pendulum 49 toward theright, only two such message circuits having been illustrated and willbe considered hereinafter.

During the cycle of operation just considered when the rotary arm Areached the stationary contact 23, the following circuit for the relaySE was momentarily closed:beginning at the terminal B of suitablebattery, wire 54, contact 13, wire ill, contact arm A stationary contact23, wire H2, upper winding of the relay SR to the other terminal C ofsaid battery. The flow of direct current in this circuit is in adirection to cause the contact 63 of the polar relay SR to be moved tothe right, thereby momentarily opening the stick circuit for the relaySR but the relay SR. will not drop, because its upper winding isincluded in series with the energized winding of the relay SR When thecontact arm A on the other hand, engages the stationary contact 24 thefollowing similar circuit is closed for the lower winding of the relaySR :-beginning at the terminal B of said battery, wire 54, contact 13,wire Ill, contact A and 24, wire I it, through the lower winding of therelay SR to the other terminal C of said battery. The flow of current inthis latter circuit is of a polarity to cause the contact 63 of therelay SR to be moved to the left, thereby momentarily interrupting thecircuit heretofore traced including the contacts 63-54 of the relay SRthe winding of the relay SR and the upper winding of the relay SR inseries, so that the relay SR will drop, but the relay SR will remainenergized, because the stick circuit for its lower winding is stillintact.

The contact arms A A and A are, of course, moved another step back tothe zero position, since the contact 4'! of relay SCR is still closed,and the relay i0 is again energized for reasons heretofore given, whichenergization of relay 10 is followed by the dropping of the relay 80, sothat the pickup circuit for the relay SCR, heretofore traced, is againcompleted, and the synchronous selector will operate through anothercycle of operation, rotating the arms A A and A through an entirerevolution to a point where all of these arms engage the zero contact.

The synchronous selector in the dispatchers office as it operatesthrough this second cycle or second revolution deenergizes the relay SRThis deenergization of the relay SR is caused by the 1 contact arm Aengaging the stationary contact 23, resulting in the operation of thecontact 63 of the relay SR toward the right, thus opening the stickcircuit for the lower winding of the relay SR. and effectingdeenergization of this relay SR With the relay SR. deenergized, and itscontact 18 opened, the relay 10 cannot again be picked up, and thereforethe relay SCR. will remain deenergized, its energizing circuit for theupper coil being opened when the contact arm A moved off of thestationary contact 24. It is thus seen that the synchronous apparatus inthe dispatchers oiiice is returned to its normal condition and broughtto rest when the arms A A and A have made two complete revolutions.

Let us now see what transpires at the way station apparatus shown at thewest end of the passing siding PS (see Fig. 1B), during the tworevolutions of operation of the dispatchers synchronous selector. Itwill be remembered that during each cycle of operation of thesynchronous selector apparatus in the dispatchers office twenty-foursuccessive negative impulses were transmitted to each of the various waystations. These negative impulses operate the various line relays suchas line relay LR toward the left once for each impulse, thus effectingrepeated energization of the electro-magnet 38 of the ratchet mechanism,thereby causing the arm 31 to be attracted by this magnet 38 andallowing it to again return to normal, through the medium of the spring35 thus causing the ratchet wheel 33 to operate one tooth for eachdeenergzation of the electro-magnet 38 and thereby causing the arms Aand A at the way station to operate in synchronism with the arms A A andA at the dispatchers oflice. The electro-magnet 38 is intermittentlyenergized, as just explained, through the following circuit:beginning atthe terminal B of a suitable battery, contact I29 of the relay LR wiresI2I and I22, winding of the electro-magnet 38 to the other terminal C ofsuch battery.

Intermittent movement of the contact I20 of the relay LR. toward theleft, also intermittently energizes the slow acting relay SLR, and sincethis slow acting relay is sufficiently slow dropping, its contact I23will remain in its attracted position during this intermittentener-gization of the line relay LR}. It is thus seen that thesynchronous selector RS located at the west end of the passing siding PSis operated one step for each operation of the synchronous selector BSin the dispatchers office.

It is, however, conceivable that the selector at the way station maylose one step or possibly gain one step, due to foreign causes such as alightning discharge and in this event the contacts A and A would notassume the zero position engaging the contact 0 when the synchronousselector apparatus in the dispatchers office reaches its normal zeroposition. In other words, the arms A and A would engage one of thestationary contacts I to 26 inclusive, with the contact I 20 of therelay LR in its normal biased position. A period of time after the linerelay LE comes to rest from its intermittent operation, the slow actingrelay SLR is deenergized thereby closing its back contact I23. This closure of the back contact I23 of the relay SLR enables the ratchetmechanism of the selector RS to intermittently energize itself throughits own back contact (a contact closed when the mechanism isdeenergized), through the following circuit:-beginning at terminal B ofa suitable battery, wire !25, contact 39 closed only when the arm 31assumes its normal position, but having sufiicient wipe to allow the arm37. to get in motion, wire I26, one of stationary contacts I to 25,inclusive engageable by the arm A arm A wire I27, back contact I23 ofthe relay SLR, wires I28 and I22, winding of the electro-magnet 58 tothe terminal C of such battery.

With this circuit available, it is obvious that the ratchet mechanism,including the pawls 3B and 3'3 the ratchet wheel 33 and theelectromagnet 38 will be operated intermittentlyto effect step by steprotation of the ratchet wheel 33 until the circuit just traced isopened, which occurs when the contact arm A reaches the zero contact 0.In other words, when intermittent operation of the line relays, such asline relay LR of each of the various Way stations ceases, thesynchronous selector apparatus at such way station is automaticallybrought to the zero position, if it does not already assume the zeroposition. Putting it another way, each synchronous selector unit locatedat a way station is self synchronizing, and returns to its normalposition when operation of the line relay for controlling the sameceases its intermittent operation.

Let us now observe how the operation of the lever L associated with theminiature passing siding ps can effect clearing of the signal S locatedat the west end of the passing siding PS. As the synchronous selectorsat the dispatchers oflice and at the way station illustrated operate insynchronism, the following circuit is closed when the contact arms A andA engage their respective stationary contacts 3:beginning at thepositive terminal of the battery IGI), wires MI and I33, lever L in itsdotted position, wire 93%, stationary contact 3, contact arm A wire I33,pendulum contact IM, line wire 46,

wire I32 (see Fig. 1B), contact arm A stationary contact 3, wires I33and I 33, winding of the signal relay KR}, wire I35, line wire 45,pendulum contact H13, wires I36 and I31, to the negative terminal of thebattery I33.

The direction of current flow in this circuit is such, that it may besaid to be of positive polarity, and causes the relay K'R to be operatedtoward the right, and in so doing closes the following pick-up circuitfor the relay KR beginning at the terminal B of a suitable battery, wireI40, contact IGI of the relay KR wires I42 and I43, winding of the relayKR wire I44, back contact I45 of the cancelling relay CR, wire I46, tothe terminal C of said battery. The momentary closure of this circuitpicks up the relay KR and this relay KR, is then struck up through thefollowing stick circuit:beginning at the terminal B of said battery,wire I'll, stick contact I48 of the relay KR wires I49 and I '53,winding of the relay KH wire I 44, contact I45, wire I46 to the otherterminal C of said battery.

With the relay KR energized, and assuming that traffic conditions inadvance as manifested by the relay H are clear, and that the switchmachine SM is in its normal straight track position, the signal S isoperated to its clear proceed position through the followingcircuit:--beginning at the terminal .8 of suitable battery, wire #58,front contact I5I of the relay KH wire I52, switch machine contact I53closed only when the switch machine is in its normal straight trackposition, wire I54, front contact I55 of the home relay H, wire I55,operating mechanism of the signal S to the other terminal C of saidbattery.

Let us now observe how the dispatcher by returning his lever L to thenormal position may again place the signal S at stop. Return of thelever L to its normal position causes momentary closure of the levercontacts 55-56-57, thereby causing the way station apparatus to beinitiated, all in a manner as already described hereinbefore, thussetting the contact arms A A A A and A into motion and rotating them insynchronism. As the arms A and A engage the stationary contact 3, andwith the pendulum 49 assuming its right hand position, the followingcircuit for the alternating current relay CR (see Fig. 1B) isclosed:starting at the secondary winding of the transformer IIiii (theprimary side of which transformer is connected to a suitable highfrequency alternating current source), wire IBI, lever contact L, wireI3I, stationary contact 3, contact arm A wire I38, pendulum contact I04,line wire 46, wire I32 (see Fig. 13), contact A stationary contact 3,wires I33 and I62, winding of the cancelling relay CR, wire I63,condenser I64 (this condenser tuning the inductance of the relay OR topermit the free flow of the particular frequency transmitted, andpreventing the flow of direct current through the relay CR), wires I65and I66, line wire 45, pendulum contact I03, wires I36, I67 andcondenser to the other terminal of the transformer.

causes it to momentarily open its contact I45, thereby opening the stickcircuit for the signal relay KR and effecting deenergization of thisrelay KR so that the signal S is again put to stop. It may be pointedout here, that this alternating current relay OR is preferably one ofthe tuned reed type, in which the contact M5 is vibrated at thefrequency of the alternating current source I63, so that this contactvI45 is open The momentary flow of alternating current in the cancellingrelay CR practically constantly during flow of current from said source.The relays IR and FSR are of similar construction.

Let us now observe how the dispatcher is informed of the passage of atrain by the signal S. Let us assume that a train has approached and hastrodden upon the detector track circuit containing the track relay TThis movement of this train upon this track circuit will of coursedeenergize the track relay T the dropping of which closes the followingcircuit for the interrupter ITR:beginning at the battery 48, wire I10,primary winding of the interrupter ITR, interrupter armature and contactI'II, wire I12, back contact I13 of the track relay T wire I14, back tobattery 49. The closure of this circuit will cause the armature I1I tobe intermittently attracted, thereby opening the circuit intermittentlyat a rate dependent upon the tuned characteristic of the armature Hi.This armature MI is preferably tuned to cause the current to beinterrupted at a predetermined rate to produce alternating current inthe secondary winding I15 of a particular desired frequency.

With the various synchronous selectors assuming their normal positions,as they ordinarily will, unless the system has been initiated by themovement of a lever or the dropping of another track relay, either ofwhich may initiate the system, the alternating current generated in thesecondary winding I15 may flow through the field starting relay FSR (seeFig. 1A) through the following circuit:beginning at the winding I15 (seeFig. 13), wire I16, condenser I11, wires I18 and I19, stationary contact0, contact arm A wire I32, line wire 46, pendulum contact I04, wire I38,contact arm A stationary contact 0, wire I89, condenser I8I, wire I82,winding of the relay FSR wires I83, I98, I31 and I35, pendulum contactI93, line wire 45, wires I66 and I84, back tothe secondary winding I15of the interrupter 1TB. The flow of current in this circuit opens thecontact I85 of the relay FSR thereby effecting deenergization of therelay FKEIR and causing closure of its contact I81.

With the contact I81 of relay FSR closed, the following pickup circuitfor the relays SR and SR is comp-leted:beginning at the terminal B, backcontact I81 of the relay FSRP, wires I88, 69 and IiI, winding of therelay SR wire 62, upper winding of the relay SR to the other terminal Cof such battery. The closure of this pick-up circuit will, of course,initiate the system in the same way that movement of the lever L, asheretofore explained, initiates the system, and this synchronousselector system will remain in operation for two complete cycles afterwhich it will be brought to stop, all in a manner as already explainedheretofore.

As the contact arms A and A assume a position to engage their respectivestationary contacts 2, the following alternating current circuit isestablished, including the winding I 15 of the interrupter ITR andincluding the indicating relay IR :beginning at the winding I15, wireI16,

condenser I11, wires I18 and I90, stationary contact 2, contact arm Awire I32, line wire 46, pendulum contact I94, wire I38, contact arm Astationary contact 2, wire I9I, condenser I92, wire I93, winding of therelay 1R wires I94, I01 and I93, I31 and I36, pendulum contact I93, linewire 35, wires I96 andIB i, back to the winding I15 of the interrupterITR.

The flow of alternating current in the circuit just traced, causes theindicating relay 1R to pick up its back contact I96, therebyinterrupting the following circuitfor the indicating relay IR :beginningat the terminal B of a suitable battery, resistance unit I91 (thisresistance unit having a resistance sufficient in value to prevent therelay 1R from picking up through this resistance but having a low enoughresistance, so that if the relay [R is once picked up it will remain inits attracted position), wire I98, winding of the indicating relay IRwire I99, back contact I96 of the relay 1R to the other terminal C ofsaid battery. For reasons just explained, if the relay IE is oncedeenergized closure of its circuit just traced and including theresistance I91 will not again effect energization of the relay IE andwith this relay IR deenergized the indicating lamp I associated with theminiature passing siding ps is illuminated by reason of closure of thefollowing circuit:-beginning at the terminal B of a suitable battery,back contact 299 of the relay 1R wire 20 I, indicating lamp I, to theother terminal C of said battery.

If now, the train in question passes oil of the detector track circuitcontaining the track relay T thereby effecting reenergization of thistrack relay T the interrupter ITR is rendered inactive, and alternatingcurrent is no longer generated in the secondary winding I15 of thisinterrupter. And under these conditions, the synchronous selectorapparatus of course being in operation at this time, it remaining inoperation for two cycles of operation after interruption in thealternating current generated by the interrupter ITR, alternatingcurrent will no longer flow to the relay 1R As the contact arm A engagesits associated stationary contact 2 and during the period of time whenthe pendulum 39 assumes its right hand position, the following pick-upcircuit for, and one not including the resistance I91 of the indicatingrelay IE is completed:-beginning at the terminal B of a suitablebattery, wire 54, pendulum contact 13, wire III, contact arm Astationary contact 2, wires 263 and I98, winding of the indicating relay1R wire I99, back contact I96 of the relay IE common return wire C.Momentary flow of current in the circuit just traced causes theindicating relay IE to assume its attracted position, and with itsarmature once assuming the attracted position, the magnetic circuit ofthe relay 1R has been improved to an extent where this relay IR remainsenergized through its normal circuit including the resistance unit I91.

As soon as the synchronous selector system now again comes to rest, theentire apparatus again assumes its normal condition, from which itappears, that the system may transmit control impulses from thedispatchers office to the distant way stations and may receiveindication impulses at the dispatchers ofiice, from any one of such waystations, and that the synchronous apparatus may be initiated from thedispatchers oflice by the movement of a lever and may be initiated fromthe field in response to the dropping of a track relay. Also, it isclear that the pendulum device PTD allots substantially half of the timefor the transmission of direct current of negative polarity forcontrolling the various synchronous selectors at the various waystations, and allots the remaining time for the purpose of transmittingmessage impulses over the same line wires 454B.

Although only one way station has been illustrated specifically, waystation No. 2 having been illustrated conventionally and designated WayStation 2", it is desired to be understood that in practice'a largenumber of way stations will be used, and that in practice all of theremaining message channels may be used all in a manner readilyunderstood from the drawings and the description heretofore given.Attention is directed to the fact .that although only the stationcontacts 0, 2 and 3 have been shown used for the message circuitsheretofore described, each of the remaining stationary contacts I and 4'to 24, inclusive, may be used for controlling other signals andindicating the occupancy of other track circuits.

Having thus shown and described only a portion of a system illustratinga rather specific embodiment of the present invention, it is desired tobe understood that the particular embodiment selected has been selectedfor the purpose of illustrating the nature of the invention and itsoperating characteristics and has not been selected for the purpose ofshowing the scope of the invention or the exact construction preferablyemployed in practicing the invention; and that various changes,modifications and additions may be made to adapt the invention to theparticular problem encountered in practicing the same, all withoutdeparting from the spirit or scope of the invention or the idea of meansunderlying the same, except as demanded by the scope of the followingclaims.

What I claim as new'is:-

1. In a train dispatching system of the synchronous selector type, incombination, a single line circuit connecting a dispatchers office and aplurality of way stations, a synchronous selector in said dispatchersoffice and a synchronous selector at each of said way stations, meansfor operating all of said synchronous selectors through the medium ofsaid line circuit by current of a particular character, a plurality ofsequentially closed message circuits each including said line circuitand contacts controlled by certain of said selectors, andelectro-responsive means included in said message circuits responsiveonly to current of a difierent character.

2. In a train dispatching system of the type in which a large number ofdevices is distinctively controlled over the same line circuit throughthe medium of a large number of sequentially selected message circuits,an electro-responsive means controlled over one of said messagecircuits, said electro-responsive means being actuated to one of itspositions in response to the flow of direct current and being actuatedto its other position in response to the flow of alternating currentover said message circuit, a timing device, and means controlled by saidtiming device for delaying the flow of current over said message circuitafter it is selected.

3. In a train dispatching system or" the synchronous selector type, thecombination with a dispatchers ofiice and a plurality of way stations ofa railway system, of a synchronous selector at said dispatchers ofliceand at each of said way stations, starting means for normally holdingsaid selectors at rest, means at each way station for applyingalternating current to said starting means to initiate said synchronousselectors into operation in response to the approach of a train to suchway station, and indicating means responsive to said alternating currentat a particular instant in a cycle of operation of said selectors forinforming the dispatcher of the approach of such train.

4. In a train dispatching-system of the syn chronous selector type, thecombination with a dispatchers ofiice and a plurality of way stations ofa railway system, of a synchronous selector at said dispatchers ofiiceand at each of said way stations, starting means for normally holdingsaid selectors at rest, means at each way station for applyingalternating current to said starting means to initiate said synchronousselectors into operation in response to the approach of a train to suchway station, indicating means responsive to said alternating current ata particular instant in a cycle of operation of said selectors forinforming the dispatcher of the approach of such train, and means forrendering said indicating means inactive just prior to said particularinstant in such cycle of operation.

5. In a centralized traffic controlling system for railroads, a controloflice, a plurality of way stations having traffic controlling devices,two line wires extending from said control ofiice through said waystations, means for placing a series of time-spaced impulses ofdistinctive characters upon said line wires, synchronous selector meansat the control office and at each way station responsive to take onestep for each alternate impulse of said series beginning with the firstimpulse, whereby a cycle of operation is completed in response to saidseries of impulses, means governing said traific controlling devices inaccordance with the character of each alternate impulse of said series,which is always different from the immediate preceding impulse,beginning with the second impulse, and means operable to selectivelydetermine the character of each alternate impulse of said seriesbeginning with the second impulse.

6. In a centralized traffic controlling system for railroads, a controloffice, a plurality of way stations having traflic controlling devices,two line wires extending from said control ofiice through said waystations, means in part automatic and in part manually operable forplacing a series of impulses of distinctive characters upon said linewires, synchronous selector means operated through a cycle of operationby said series of impulses, and means responsive to the character ofcertain of said impulses, which are always different from the immediatepreceding impulse, to distinctively operate said trafiic governingdevices, said means being responsive to the order of said impulses in amanner to determine which of said trafiic governingdevices is to bedistinctively operated, whereby said devices are manually governed fromsaid control office.

'7. In a centralized trafilc controlling system for railroads, adispatchers office, a plurality of way stations having traffic governingdevices, two line wires extending from the dispatchers oflice throughthe several way stations, means at the dispatchers ofiice for applying'aseries of timespaced impulses of a particular distinctive character tosaid line wires, step-by-step means at the dispatchers oflice and ateach Way station responsive to take one step for each of said timespacedimpulses, means at the dispatchers office and at each way station forcompleting a plurality of message channels over said line wires, one foreach step, said means including in part said step-by-stepmeans,electro-responsivemeans on certain of said message channelsresponsive to impulses always of certain other distinctive characters,whereby said trafiic governing devices may be controlled and theircondition indicated in the dispatchers ofiice.

' 8. Ina train dispatching system, a plurality of devices, a single linecircuit for connection to the devices, means for connecting the linecircuit to the devices through sequentially selected message circuits,an electro-responsive means included in one of the message circuits,said electro-responsive means being distinctively actuated in responseto the flow of direct current and being distinctively actuated inresponse to the flow of alternating current over said message circuit, atiming device, and means controlled by said timing device for delayingthe flow of current over said message circuit after it is selected.

9. In a train dispatching system of the type in which a large number ofdevices are distinctively controlled over the same line circuit throughthe medium of a large number of sequentially selected message circuits,an electroresponsive means included in a message circuit,

said electro-respo-nsive means being caused to assume a distinctivecondition in response to the flow of direct cmrent and being caused toassume a distinctive condition in response to the flow of alternatingcurrent over said message circuit, a timing device, means controlled bysaid timing device for delaying the flow of current over said messagecircuit after it is selected, and means for storing one distinctivecondition of said electro-responsive means until said electroresponsivemeans is caused to assume another distinctive condition.

10. In a train dispatching system of the synchronous selector type, thecombination with a dispatchers office and a plurality of way stations ofa railway system, of a synchronous. selector at said dispatchers officeand at each of said way stations, starting means for" normally holdingsaid selectors at rest, means at each way station for applyingalternating current to said starting means to initiate said synchronousselectors into operation, and indicating means responsive to saidalternating current at a particular instant in a cycle of operation ofsaid selectors for informing the dispatcher of trafiic conditions.

ll. In a centralized trafiic controlling system, in combination,synchronous apparatus at a central oifice and at a plurality of waystations, a single line circuit connecting the offi'ce and way stations,means for allotting alternate times to the line circuit for synchronouscontrol and for message circuit purposes respectively, and means forinitiating the synchronous operation from the central office and fromany Way station by respectively different characters of currents.

12. In a centralized tramccontrolling system, in combination,synchronous apparatus at a central office and at a plurality of waystations, a single line circuit connecting the office and way stations,means for allotting alternate times to the line circuit for synchronouscontrol and for message circuit purposes respectively, and means forinitiating the synchronous operation from the central office and fromany way station by direct current and alternating current respectively.

13. In a centralized traffic control system, in combination, synchronousapparatus at a central office and at a plurality of way stations, asingle line circuit connecting the office and way station, means forallotting alternate times to the line circuit for synchronous controland for message circuit purposes respectively, means for initiating thesynchronous operation from the central office and from any way stationby respectively different characters of currents, means at the waystation controlled over the message circuit in a distinctive manner inaccordance with current of a distinctive character, and means at thecentral oilice for indicating traiiic conditions and controlled over themessage circuit by current different from the stepping current.

14. In a centralized trafiic controlling system, in combination,synchronous apparatus at a central office and at a plurality of waystations, a single line circuit connecting the oifice and Way stations,means for allotting alternate times to the line circuit for synchronouscontrol and for message circuit purposes respectively, and means forinitiating the synchronous operation from the central oflice and fromany Way station by respectively different characters of currents, thedifferent characters of currents being direct and alternating. I

15. In a traffic control system, in combination with a control officeand a plurality of way stations, a single line circuit connecting thecentral oflice and way stations; step-by-step means at the centralofliceand the way stations, means for operating the step-by-step meansover the line circuit by one character of current, control means at theway stations, means for operating the control means over the linecircuit by another character of current, and means for initiating thestep-by-step means and causing an indication in the central oflice, bystill another character of current.

16. In a tramc control system, in combination with a control office anda plurality of way stations, a single line circuit connecting thecentral office and way stations; step-by-step means at the centraloflice and the way stations, means for operating the step-by-step meansover the line circuit by one character of current, control means at theWay stations, means for operating the control means over the linecircuit by either of two other characters of current, and means forinitiating the step-by-step means and causing an indication in thecentral office, by still another character of current.

1'7. In a centralized traffic controlling system, in combination,step-by-step means at a central office and at a way-station beingoperable in synchronism when initiated, a single line circuit connectingthe oflice and way-station, means for allotting alternate times for eachstep to condition the line circuit for different purposes, and means forinitiating the step-by-step operation from the central oiiice and fromthe way-station by respectively different characters of current.

18. In a train dispatching system of the synchronous selector type, incombination, a single line circuit connecting a dispatchers office and aplurality of way stations, a synchronous selector in said dispatchersoflice and a synchronous selector at each of said way stations, a devicehaving a natural time period of operation, means including said devicefor energizing said line circuit with a plurality of time spacedimpulses, means responsive only to certain of said impulses foroperating all of said synchronous selectors, a plurality of sequentiallyclosed message circuits each including said line circuit and contactscontrolled by certain of said selectors, and means including said devicefor allotting the use of said line circuit alternately for the purposeof controlling said synchronous selectors and for the purpose ofestablishing such message circuits.

19. In a traffic control system, in combination with a control ofiiceand a plurality of way stations, a single line circuit connecting thecentral ofiice and way stations; step-by-step means at the controlofiice and the Way stations, means for operating the step-by-step meansover the line circuit by one polarity of current, control means at theWay stations, means for operating the control means over the linecircuit by the other polarity of current and by alternating current ofone frequency, and means for initiating the step-by-step means andcausing an indicaticn in the central oifice by alternating current of adifierent frequency.

20. In a centralized tramc controlling system for railroads; a linecircuit connecting a control ofiice and a field station; impulsing meansfor energizing said line circuit with a series of time spaced impulses;a normally at rest step-by-step means at said control ofiice and saidfield station operable in synchronism, when initiated, in response toimpulses on said line circuit; means including said impulsing means forsuccessively allotting said line circuit on each step of saidstepby-step means for two difierent purposes; means to! manuallyinitiating said step-by-step means from said control ofiice; and meansefiective over said line circuit for at times automatically initiatingsaid step-by-step means.

21. In a centralized trafilc controlling system for railroads; a linecircuit connecting a control oflice and a field station; ,impulsingmeans for energizing said line circuit with a series of time spacedimpulses; a normally at rest step-by-step means at said control officeand said field station operable in synchronism, when initiated, inresponse to impulses on said line circuit; means including saidimpulsing means for successively allotting said line circuit on eachstep for two different purposes and including timing means whollylocated at the control ofiice for determining the respective periods ofallotment; means for manually initiating said step-by-step means fromsaid control ofiice; and means effective for at times automaticallyinitiating said step-by-step means.

22. In a centralized trafiic ccntrolling system for railroads; a linecircuit connecting a control oflice and a field station; a normally atrest stepby-step means at said control office and said field stationoperable in synchronism, when initiated, in response to impulses on saidline circuit;-impulsing means for impressing a series of impulses onsaid line circuit; means including said impulsing means for successivelyallotting said line circuit subject to control by said control officeand said field station respectively on each step, and including timingmeans wholly located at said control ofiice for determining therespective periods of allotment; means for manually initiating saidstep-by-step means from said control office; and means for at timesautomatically initiating said step-by-step means from said fieldstation.

23. In a train dispatching system of the synchronous selector type, adispatchers office and a plurality of way stations connected by a singleline circuit, a selector at said oilice and a selector at each of saidstations, a time control device,

, means including said device for energizing said line circuit withseries of time spaced impulses, a plurality of sequentially closedmessage circuits each including said line circuit and contacts of saidselectors, and means controlled by said device for allotting alternateimpulses of a series only for the control of said selectors andintervening impulses of said series only for the establishment of saidmessage circuits;

24. In a remote control system, a line circuit having a plurality ofseries oftime spaced stepping impulses impressed thereon, step-by-stepmechanisms operable through a separate cycle for each of said series ofstepping impulses, means controlled by said mechanisms for selectinglocal channel circuits for each step, means for interposingcharacteristic message carrier impulses on said line circuit betweensaid stepping impulses, means for causing said mechanisms to take onestep for each of said stepping impulses, and means for distinctivelyenergizing said channel circuits in accordance with the character ofsaid message carrier impulses.

25. In a remote control system, a line circuit having a plurality ofseries of time spaced stepping impulses of a first character impressedthereon, step-by-step mechanisms operable through a separate cycle foreach of said series of stepping impulses, means controlled by saidmecha-- nisms for selecting local channel circuits for each step, meansfor selectively interposing message carrier impulses of a second orthird character on said line circuit between said stepping impulses,means for causing said mechanisms to take one step for each of saidstepping impulses, andmeans for distinctivelyenergizing said channelcircuits in accordance with the character of said message carrierimpulses.

26. In a remote control system, a line circuit having a plurality ofseries of time spaced stepping impulses impressed thereon, step-by-stepmechanisms operable through a separate cycle for each of said series ofstepping impulses, means controlled by said mechanisms for selectinglocal channel circuits for each step, means for interposingcharacteristic message carrier impulses on said line circuit betweensaid stepping impulses,

means for preparing said mechanisms to take one step for each of saidstepping impulses, means for causing said mechanisms to complete onestep for each time space between said stepping impulses, and means fordistinctively energizing said channel circuits in accordance with thecharacter of said message carrier impulses.

27. Remote controlling apparatus comprising a line Wire connecting anoflice and a station, manually controlled means at said office for attimes initiating said apparatus, automatic means at said station for attimes delivering a starting impulse to said line wire for initiatingsaid apparatus, means operating in response to such initiation from saidstation to deliver a series of alternate control and indication impulsesto said line wire, and means selectively controlled by said control andindication impulses.

' RAY PLANK.

